1

ASF Response

Depopulation, Disposal, and Decontamination 

Guidance—Option Matrices and Considerations

November 2019

PURPOSE

The purpose of this document is to provide a summary of scientific data and best practices related to depopulation, disposal, 

and decontamination, also known as 3D, in the case of an African Swine Fever (ASF) outbreak emergency response. Other 

tools are available on the APHIS Carcass Management website: 

https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/emergency-management/carcass-management.

USAGE 

This information is intended to assist planners and responders in quickly identifying possible 3D alternatives during an ASF 

response. Do note that the data provided here is typically based on scientific research, and not necessarily based on field 

experience. If government policy is developed from this data, the resulting standard may have a factor of safety making the 

standard considerably higher than the research data point. For example, although research showed natural inactivation of 

ASF virus to occur after 15.3 days at 400F in swine urine, it doesn't mean the farm only has to remain fallow for 15.3 days; the 

ultimate standard will likely be much longer.

This document is divided into three separate sections correlating to each 3D topic with matrices covering options, 

applicability, efficacy, limitations and related references. In addition to matrices, other helpful information may be included. 

CONTRIBUTORS

The information provided in this document was compiled by USDA APHIS based on publicly available research articles, a 

compilation of ASF-related studies developed by the Canadian Food Inspection Agency, and a summary of depopulation 

information developed by Carthage System Professional Swine Management, LLC.

This document was reviewed by numerous USDA staff and the National Pork Board.

Please address any questions or suggestions for improvement to lori.p.miller@usda.gov or robert.a.miknis@usda.gov.
3D OPTION MATRICES AND CONSIDERATIONS—DEPOPULATION 2

DEPOPULATION 

Inhalant 

(CO2 gas) Gun Shot* Nonpenetrating Captive Bolt

Penetrating 

Captive Bolt

Electrocution 

Head to Heart**

Veterinarian 

Administered 

Anesthetic 

Overdose 

(Injectable)

Ventilation 

Shutdown (VSD) Sodium Nitrate

AVMA 2019 

Approved?

Yes Preferred 

Method

Yes Preferred 

Method

Yes Preferred 

Method

Yes Preferred 

Method

Yes Preferred 

Method on pigs over 

10 lbs.

Yes Preferred 

Method

Yes – as VSD Plus† Yes – feral swine

Permitted in 

Constrained 

Circumstances

Permitted in 

Constrained 

Circumstances

Swine Size∆ S S,M,L S M,L M,L S,M,L S,M,L S,M,L

Risk to Human 

Safety Moderate High Moderate Moderate

Low if proper lock 

out/tag out 

procedure is 

followed

Low if proper 

animal restraint 

is used

Low Low

Skill Required

Moderate to low, 

based on 

equipment design

Moderate to high Moderate Moderate Moderate

High, veterinary 

administration 

only

Not described in the NPB/AASV On-Farm 

Euthanasia of Swine Recommendations

Low, must 

understand the 

system and human 

safety

Low, must dose 

each animal 

individually

Aesthetics

Bloodless, some 

excitatory 

movement or 

vocalization 

possible

Discharge of blood 

from wound

Operator / observer 

impact, may have 

some blood

Discharge of blood 

from wound Muscle contraction

No blood 

discharge, limited 

pig movements

Vocalization 

possible Minimal

Limitations

• Currently only 

studied by US 

on small pigs up 

to 70 lbs.

• Improved 

methods being 

evaluated for 

larger animals. 

• Scarcity of CO2.

• Security of 

firearms.

• Legal restrictions.

• Scarcity of 

trained people 

with sufficient 

equipment and 

supplies.

• Maintenance.

• Use only in 

suckling and 

nursery pigs.

• Requires proper 

restraint.

• Scarcity of 

trained operators 

and suitable 

equipment.

• May be a twostep process

depending on 

equipment 

design.

• Requires proper 

restraint.

• Scarcity of 

trained operators 

and suitable 

equipment.

• Adequate 

amperage needed.

• Commercial hog 

stunner 

recommended.

• Head only is a 

two-step process.

• Scarcity of trained 

personnel, 

equipment and 

power supply.

• Applicable 

agents 

available only 

to licensed 

veterinarians.

• Limits carcass 

disposal 

options.

• Scarcity of 

enough drugs 

for whole farm.

• Only in 

constrained 

circumstances.

• Significant labor 

requirement 

(disposal).

• Enclosure must 

have ability to be 

adequately 

sealed.

• May not be 100% 

effective.

• Only in 

constrained 

circumstances.

• Scarcity of 

sodium nitrite.

Caracas Disposal 

Restrictions No No No No No Yes No No

Biosecurity Risk 

– Blood

Contamination?

No Yes No Yes No No No No

Table adapted from Carthage System Professional Swine Management, LLC.

* Not for suckling pigs.

** Head to Heart applications can be one step if done properly. Head only electrocution requires secondary method be applies within 15 seconds (e.g., heart electrocution, exsanguination). 

† Ventilation shutdown involves closing up the house, closing all inlets, and turning off fans. The animals die from hyperthermia. VSD can only be used in facilities that can adequately be sealed to increase 

air temperature. The Plus component is the addition of supplemental heat or CO2 to better achieve a high death rate. ∆ S = small pigs up to 100 pounds, M = medium pigs between 100 and 300 pounds, & L = large pigs over 300 pounds.
3D OPTION MATRICES AND CONSIDERATIONS—DISPOSAL 3

DISPOSAL 

Carcass Management Options—An Overview (from L.P. Miller, USDA, 2018)

1. Test negative animals to slaughter or non-infected disposal

2. Composting – likely to inactivate ASFv by multiple mechanisms

3. Above Ground Burial – likely to inactivate ASFv by multiple mechanisms

4. Deep Burial – unlikely to inactivate ASFv

5. Burning:

a. Open burning – likely to inactivate ASFv, but also potential to cause adverse human health impacts

b. Mobile incineration – safer then open burning but limited throughout

6. Landfill – negligible risk if leachate goes into wastewater treatment step; prioritize ASF-negative herds for landfill to virtually eliminate risk

7. Rendering – prioritize ASF-negative herds for rendering if renderers will accept non-infected material from infected premises or control area

8. Incineration/energy-from-waste – highly likely to inactivate ASFv but requires packaging carcasses 

Carcass Management Considerations (state disposal laws at https://www.vetca.org/lacd/index.php)

Applicability Efficacy/Effectiveness Limitations References

Controlled Marketing • Test-negative animals

• Would greatly reduce the 

amount of material for disposal 

and conserve a valuable protein 

resource.

• Currently no validated whole-herd 

test available; challenging to collect 

samples from individual animals.

• Consumers may reject products 

from control areas.

Separate Test Negative 

animals for non-infected 

disposal and infected 

animals for on-site 

management or off-site 

infected disposal

• If permitted by AHOs.

• If negative status can be 

certified as required by disposal 

facility.

• If premises can be separated 

into clean/dirty areas.

• If strict biosecurity can be 

maintained.

• Would reduce amount of 

material for on-site or infected 

off-site management, provide 

more disposal options, and 

reduce disposal costs.

• Currently no validated whole-herd 

test available; challenging to collect 

samples.

• Disposal facilities may reject 

products from control areas.

Burial - Deep

• If allowed by state 

environmental regulators.

• In an area deemed to have 

suitable soils.

• Allowed by property owner. 

• Removes carcasses from view, 

but not likely to destroy ASF or 

biomass.

• Results in permanent burial site 

which may require recording on 

property deed (0.1 acres per (1200) 

200-pound pigs).

• Does not inactivate pathogens or 

destroy biomass.

• Allows leachate to discharge directly 

to environment.

• Borchardt et al, “Avian Influenza Virus RNA in 

Groundwater Wells Supplying Poultry Farms 

Affected by the 2015 Influenza Outbreak”, 

Environmental Science and Technology Letters, 

American Chemical Society, 2017.

• Freedman et al, “Water Quality Impacts of Burying 

Livestock Mortalities”, Ridgetown College, 

University of Guelph, 2003.

• MacArthur, et al, “Leachate characteristics and 

management requirements arising from the foot 

and mouth operations in Scotland”, Journal of 

Swine Health and Production, 2001.

• Pratt et al, “Livestock Mortalities Burial Leachate 

Chemistry after Two Years of Decomposition”, 

Biocycle, 2009.

• Qi et al, “Potential Water Quality Impacts 

Originating from Land Burial of Cattle Carcasses”, 

University of Nebraska, 2013.
3D OPTION MATRICES AND CONSIDERATIONS—DISPOSAL 4

Applicability Efficacy/Effectiveness Limitations References

Burning - Open/Air 

Curtain

• If allowed by state 

environmental regulators and 

public health authorities.

• If allowed by fire control 

authorities. 

• Destroys ASF and biomass 

resulting in 5 % ash.

• Logistically challenging.

• Slow.

• Potential public health risk.

• Watkiss et al, "Cost Benefit Analysis of Foot and 

Mouth Disease Control Strategies: Environmental 

Impacts", AEA Technology Environment Report, 

2004.

Burning - Mobile gasifier 

or similar

• If allowed by state 

environmental regulators and 

public health authorities.

• If allowed by fire control 

authorities.

• Destroys ASF and biomass 

resulting in 5 % ash.

• Safer than open burning/air 

curtain.

• Limited availability.

• Processes up to 2 tons/hour.

Composting

• If allowed by state 

environmental regulators.

• In an area with suitable soils.

• Likely to destroy ASF.

• Converts biomass to useful byproduct.

• Requires 1:1 ratio of wood chips to 

carcass weight.

• Requires adequate space for 

windrows (1 acre per (1200) 200-

pound pigs).

• Takes up to a year for whole 

carcasses to fully compost.

• Requires routine temperature 

monitoring.

• Requires expertise to properly 

construct windows.

• Not yet validated for ASF inactivation.

• Glanville et al. Environmental Impacts of 

Emergency Livestock Mortality Composting—

Leachate Release and Soil Contamination (Iowa 

State University, 2006)

• Bonhotal et al. Evaluating Pathogen Destruction in 

Road Kill Composting. Cornell University. 

BioCycle, 47(11):49-51, 2006.

• Guan et al. Degradation of foot-and-mouth 

disease virus during composting of infected pig 

carcasses. Can J Vet Res. 2010.

Burial - Above Ground

• If allowed by state 

environmental regulators.

• In an area with suitable soils.

• Experimental – may destroy 

ASF.

• Experimental – may decompose 

biomass over time.

• Requires 1:5 ratio of wood chips to 

carcass weight.

• Requires adequate space for plots 

(0.3 acres per (1200) 200-pound 

pigs).

• Takes up to a year for whole 

carcasses to fully decompose if 

abdomen is lanced.

• Requires routine maintenance of 

plots.

• Not yet studied for ASF inactivation.

• Flory et al. Mesophillic Static Pile Composting Of 

Animal Carcasses. BioCycle March/April 2017, 

Vol. 58, No. 3, p. 65.

Landfill

• For non-infected carcasses from 

control area.

• If infected carcass transport is 

permitted by veterinary health 

authorities.

• If landfill will accept infected 

carcasses.

• Removes carcasses from view, 

but does not destroy ASF 

biomass.

• Protective of public health if 

landfill in compliance with permit 

requirements.

• Does not inactivate pathogens or 

destroy biomass.

• Requires trucks to be lined.

Rendering

• For non-infected carcasses from 

control area if renderer accepts.

• If infected carcass transport is 

permitted by veterinary health 

authorities.

• If rending plant will accept 

infected carcasses.

• Destroys pathogens.

• Converts biomass to useful 

byproducts.

• Designed for carcass 

management.

• Infected material may disrupt 

rendering company business.

• Unlikely to be fully biosecure.

• Requires trucks to be lined.

• Hayes, Mary, "Validation of Thermal Destruction of 

Pathogenic Bacteria in Rendered Animal 

Products" (2013).

Incineration/

energy-from-waste

• If infected carcass transport is 

permitted by veterinary health 

authorities.

• If incinerator will accept infected 

carcasses.

• Destroys ASF and biomass.

• Produces energy.

• Limited availability.

• Requires packaging carcasses into 1 

cubic yard lined boxes.
3D OPTION MATRICES AND CONSIDERATIONS—DECONTAMINATION 5

DECONTAMINATION 

Outdoor 

Areas

Treatment Applicability Efficacy/Effectiveness Limitations References

Chemical 

Disinfectants 

(except hydrated 

lime)

Not recommended 

because presence of soil 

reduces disinfection 

efficacy and due to 

potential environmental

Calfee, W. Effectiveness of Spray-Based 

Decontamination Methods for Spores and 

Viruses on Heavily Soiled Surfaces. EPA. 2016.

Heat Disinfection Possible; some use of 

flame on earthen surfaces

High temperatures inactivate 

pathogens

• Limited availability of 

equipment and fuel.

• Risk of fuel.

• Surface treatment only.

Hydrated Lime Applicable Inactivates pathogens except 

pseudomonas sp.

• Surface treatment only

• Human health risks when 

handling.

Schotsmans et al. Short-term effects of hydrated 

lime and quicklime on the decay of human 

remains using pig cadavers as human body 

analogues: Laboratory experiments. 2014.

Fallowing Applicable Urine non-infective at 40C after 15.3 

days

Davies et al. Survival of African Swine Fever 

Virus in Excretions from Pigs Experimentally 

Infected with the Georgia 2007/1 Isolate. 

Pirbright Institute. 2015.

Structures

Treatment Applicability Efficacy/Effectiveness Limitations References

Cleaning and 

Disinfection 

(C&D)*, followed 

by application of 

an EPA registered 

antimicrobial** 

Interior surfaces of barns

Routinely shown effective during 

outbreaks with post C&D sampling 

analysis.

• Generates large volumes 

of wastewater for 

collection/treatment.

• Labor intensive.

• Relatively expensive.

• APHIS HPAI guidance can be found at 

https://www.aphis.usda.gov/animal_health/em

ergency_management/downloads/hpai/cleani

ng_disinfection.pdf.

• Approved ASF Disinfectants can be found at 

https://www.aphis.usda.gov/animal_health/em

ergency_management/downloads/asf-virusdisinfectants.pdf. 

Interior surfaces of packing 

plants

Disinfection of pork packing plants 

should be done with acid-based 

disinfectants (such as CD631) 

following manufacturer’s instructions 

particularly regarding pre-washing 

procedures.

Hypochlorite based 

disinfectants such as XY12 

and bleach should be 

avoided when organic load 

(e.g. blood, feces) is high.

https://www.pork.org/research/disinfection-offoreign-animal-disease-viruses-on-surfacesrelevant-to-the-pork-packing-industry/

Dry cleaning and 

heat∆ Interior surfaces of barns

Usually shown effective during 

outbreaks with post C&D sampling 

and analysis. 

May require auxiliary 

heaters/equipment that must 

be decontaminated.

APHIS HPAI guidance can be found at 

https://www.aphis.usda.gov/animal_health/emer

gency_management/downloads/hpai/cleaning_d

isinfection.pdf.

Fumigation (ClO2) Interior surfaces of barns Effective for HPAI and MS2 phage

• Can corrode metals.

• Only works on clean 

surfaces.

EPA/The Sabre Companies, available upon 

request 

* The removal of gross contamination, organic material, and debris from the premises, via mechanical means like sweeping (dry cleaning) and/or use of water and soap or detergent (wet cleaning).

** See reference column for registered antimicrobials; application rates and contact times are found on product labels.

∆ The removal of gross contamination, organic material, and debris from the premises, via mechanical means like sweeping (dry cleaning) followed by heating at 1000F - 1200F for 7 days total.
3D OPTION MATRICES AND CONSIDERATIONS—DECONTAMINATION 6

Vehicles/ 

Equipment

Treatment Applicability Efficacy/Effectiveness Limitations References

Wet cleaning & 

disinfection All exterior vehicle surfaces Shown effective during field trials with post C&D sampling and analysis

• Generates wastewater 

possibly requiring 

collection/treatment.

• Labor intensive unless 

automated.

• Relatively expensive.

Guan et al. Vehicle and Equipment 

Decontamination During Outbreaks of Notifiable 

Animal Diseases in Cold Weather. 2017.

“Baking”

Used by the pork industry 

for livestock trailers and 

PEDv

Unknown effectiveness for ASF

May require auxiliary 

heaters/equipment that must 

be decontaminated

Holtkamp et al. Evaluation of time and 

temperature sufficient to inactivate porcine 

epidemic diarrhea virus in swine feces on metal 

surfaces. 2014

Manure/ 

Slurry

Treatment Applicability Efficacy/Effectiveness Limitations References

Heat – slurry

Efficacious after 24 hours 

@ 500C (1220F) or 15 

minutes @ 600C (1400F)

Depends on solids concentration.

May pose logistical 

challenges – needs field 

validation.

Turner et al. Laboratory-scale inactivation of 

African swine fever virus and swine vesicular 

disease virus in pig slurry. Pirbright Institute. 

1999.

Heat – manure, 

urine, saliva

Efficacious after 15.3 days 

@ 40C (400F)

Davies et al. Survival of African Swine Fever 

Virus in Excretions from Pigs Experimentally 

Infected with the Georgia 2007/1 Isolate. 

Pirbright Institute. 2015.

1% Sodium or 

Calcium 

Hydroxide 

wt/volume - slurry

Efficacious after 5 minutes 

@ 40C (400F) Depends on solids concentration

Worker health/safety risk 

from potential chemical 

burns and inhalation 

chemicals

Turner et al. Laboratory-scale inactivation of 

African swine fever virus and swine vesicular 

disease virus in pig slurry. Pirbright Institute. 

1999.